[0/5] PCI: Add PCI_ERROR_RESPONSE, check for errors

Message

Bjorn Helgaas Aug. 5, 2019, 8:52 p.m. UTC

From: Bjorn Helgaas <[e-mail]>

Reads from a PCI device may fail if the device has been turned off (put
into D3cold), removed, or if some other error occurs.  The PCI host bridge
typically fabricates ~0 data to complete the CPU's read.

We check for that in a few places, but not in a consistent way.  This
series adds a PCI_ERROR_RESPONSE definition to make the checks more
consistent and easier to find.  Note that ~0 may indicate a PCI error, but
it may also be valid read data, so you need more information (such as
knowing that a register can never contain ~0) before concluding that it's
an error.

This series also adds some new checks for PCI_ERROR_RESPONSE in the power
management code because that code frequently encounters devices in D3cold,
where we previously misinterpreted ~0 data.

Bjorn Helgaas (5):
  PCI: Add PCI_ERROR_RESPONSE definition
  PCI / PM: Return error when changing power state from D3cold
  PCI / PM: Check for error when reading PME status
  PCI / PM: Check for error when reading Power State
  PCI / PM: Decode D3cold power state correctly

 drivers/pci/access.c                          | 13 +++----
 .../pci/controller/dwc/pcie-designware-host.c |  2 +-
 drivers/pci/controller/pci-aardvark.c         |  2 +-
 drivers/pci/controller/pci-mvebu.c            |  4 +-
 drivers/pci/controller/pci-thunder-ecam.c     | 20 +++++-----
 drivers/pci/controller/pci-thunder-pem.c      |  2 +-
 drivers/pci/controller/pcie-altera.c          |  2 +-
 drivers/pci/controller/pcie-iproc.c           |  2 +-
 drivers/pci/controller/pcie-mediatek.c        |  4 +-
 drivers/pci/controller/pcie-rcar.c            |  2 +-
 drivers/pci/controller/pcie-rockchip-host.c   |  2 +-
 drivers/pci/controller/vmd.c                  |  2 +-
 drivers/pci/hotplug/cpqphp_ctrl.c             | 12 +++---
 drivers/pci/hotplug/cpqphp_pci.c              | 20 +++++-----
 drivers/pci/hotplug/pciehp_hpc.c              |  6 +--
 drivers/pci/pci.c                             | 38 ++++++++++++-------
 drivers/pci/pcie/dpc.c                        |  3 +-
 drivers/pci/pcie/pme.c                        |  4 +-
 drivers/pci/probe.c                           |  4 +-
 drivers/pci/quirks.c                          |  2 +-
 include/linux/pci.h                           | 20 ++++++++++
 21 files changed, 98 insertions(+), 68 deletions(-)